It has been proposed that the sleep cycle is actively generated by two interrelated cell aggregations in the rostral pons: the locus coeruleus and the nearby giant cells of the pontine tegmentum. The hypothesis invites a thorough pharmacological investigation. Drugs are delivered to the two pontine areas mentioned above, using push-pull cannulae, and the resulting effects upon sleep-wakefulness behavior of freely moving animals (cats) are assessed with a sleep-wakefulness polygram. The studies relate directly to human disease states in which the sleep cycle is out of control--narcolepsy, depression, and the withdrawal from drug (including alcohol) addiction.